Data conversion device for a reed-solomon decoder

Abstract

A data converter device for a Reed-Solomon decoder receives a first data stream (d 1 ) and a second data stream (d 2 ). The first data stream (d 1 ) is input to the Reed-Solomon decoder, whose decoding process is defined by a first primitive polynomial, either directly or via a first intermediate processing stage. The second data stream (d 2 ) is conducted to a code converter, either directly or via a second intermediate processing stage. The code converter performs an isomorphic imaging process. After the Reed-Solomon decoder a second isomorphic imaging process of these converted data, inverse to the first one, is performed by a second code converter.

What is claimed is:  
     
         1 . A data conversion device for a Reed-Solomon decoder, which is fed with at least a first and a second data stream from a data source in time multiplex operation, the data of said data streams corresponding respectively to a first and second Reed-Solomon code, with an associated first and second primitive polynomial different from one another but of the same order, said device comprising: 
 a first intermediate processing stage that receives the first data stream (d 1 ) and provides a ninth data stream (d 9 ) to a Reed-Solomon decoder whose decoding process is defined by the first primitive polynomial and at least a first generator polynomial;    a second intermediate processing stage that receives the second data stream (d 2 ) and provides a third data stream (d 3 ) to a first code converter ( 11 ) that performs an isomorphic imaging process of the data associated with the second primitive polynomial into data which are associated with the first primitive polynomial, wherein said first code converter provides a fourth data stream (d 4 ) output signal that is input to said Reed-Solomon decoder; and    wherein said Reed-Solomon decoder selectively provides as an output signal one of a fifth data stream (d 5 ) and a sixth data stream (d 6 ); and    a second code converter that performs an isomorphic imaging process inverse to said first code converter, and converts said sixth data stream (d 6 ) into a seventh data stream (d 7 ) whose primitive polynomial is the second primitive polynomial.    
     
     
         2 . The device of    claim 1   , wherein said first and second intermediate processing stages each include a Viterbi decoder.  
     
     
         3 . The device of    claim 1   , wherein: 
 a single Viterbi decoder is present for said first and second intermediate processing stages;    in the first operating mode, the single Viterbi decoder is fed by the first data stream (d 1 ) or by a tenth data stream (d 10 ) depending on it, and its output is connected directly to the input of said Reed-Solomon decoder; and    in the second operating mode, said single Viterbi decoder is fed by an eighth data stream (d 8 ), which depends on the second data stream (d 2 ), and its output is connected, via said first code converter to the input of said Reed-Solomon decoder.    
     
     
         4 . The device of    claim 2    wherein said second intermediate processing stage comprises a buffer device that receives said second data stream and provides a buffered eight data stream (d 8 ) to said Viterbi decoder.  
     
     
         5 . The device of    claim 1   , wherein said first and second code converters include a stored table or a subprogram to convert the data.  
     
     
         6 . The device of    claim 5   , wherein the data of the seventh data stream (d 7 ) which controls said first and second operating modes through a control device, are stored in said device in a static memory.  
     
     
         7 . The device of    claim 1   , further comprising a signal processor that receives and processes said fifth data stream (d 5 ).  
     
     
         8 . A data conversion device for a Reed-Solomon decoder that receives a first and a second data stream that correspond to a first and second Reed-Solomon code respectively with an associated first and second primitive polynomial different from one another but of the same order, said device comprising: 
 means for receiving and processing the first data stream (d 1 ), and for providing a ninth data stream (d 9 ) to a Reed-Solomon decoder whose decoding process is defined by the first primitive polynomial and at least a first generator polynomial;    means for receiving and processing the second data stream (d 2 ), and for providing a third data stream (d 3 ) to a first code converter that performs an isomorphic imaging process of the data associated with the second primitive polynomial into data which are associated with the first primitive polynomial, wherein said first code converter provides a fourth data stream (d 4 ) output signal that is input to said Reed-Solomon decoder; and    wherein said Reed-Solomon decoder selectively provides as an output signal one of a fifth data stream (d 5 ) and a sixth data stream (d 6 ); and    means for performing an isomorphic imaging process that is inverse to said first code converter, and for converting said sixth data stream (d 6 ) to a seventh data stream (d 7 ) whose primitive polynomial is the second primitive polynomial.